Conventionally, a working vehicle is known in which a working machine is connected to a vehicle body and the working machine is driven via a PTO shaft. For example, an agricultural tractor described in the Patent Literature 1 (the Japanese Patent Laid Open Gazette 2010-172197) is so.
In the agricultural tractor described in the Patent Literature 1, the working machine (rotary tilling device) is connected to a rear part of the vehicle body and the working machine can be via the PTO shaft. In the agricultural tractor described in the Patent Literature 1 (the Japanese Patent Laid Open Gazette 2010-172197), a vehicle operation instrument (forward/rearward traveling switch lever) which is operated so as to make the vehicle body travel rearward is provided. In a basal end part of the vehicle operation instrument, a reverse switch (back switch) detecting the operation of the vehicle operation instrument to the rearward traveling side is provided. In the tractor configured as the above, for preventing drive of the PTO shaft at the time of rearward traveling of the vehicle body, during the operation of the vehicle operation instrument to the rearward traveling side is detected by the reverse switch, in principle, a control device performs control so as not to transmit power from an engine to the PTO shaft.
The reverse switch has a circuit in which a contact which is normally opened type is arranged and attached to the vehicle body so that when the vehicle operation instrument is operated to the rearward traveling side, the contact is closed, and when the vehicle operation instrument is not operated to the rearward traveling side, the contact is opened.